Metabolic engineering of anE. coli ndhknockout strain for PHB production from mixed glucose-xylose feedstock
| Autor: | Ran Tao, Qiaojie Liu, Na Diao, Guangxin Huo, Yuhong Zhu, Zhiwen Wang, Tao Chen |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Arabinose Xylose isomerase Strain (chemistry) biology Renewable Energy Sustainability and the Environment Chemistry General Chemical Engineering Organic Chemistry Bacillus subtilis Xylose biology.organism_classification Pollution Inorganic Chemistry Metabolic engineering 03 medical and health sciences chemistry.chemical_compound 030104 developmental biology Fuel Technology Biochemistry Xylulokinase Fermentation Waste Management and Disposal Biotechnology |
| Zdroj: | Journal of Chemical Technology & Biotechnology. 92:2739-2745 |
| ISSN: | 0268-2575 |
| DOI: | 10.1002/jctb.5298 |
| Popis: | BACKGROUND Poly(3-hydroxybutyrate) (PHB), which is completely biodegradable, is considered a potential candidate to replace a number of petroleum-derived polymers due to similar mechanical properties. In a previous study, inactivation of ndh gene in E. coli, which encodes the NDH-II dehydrogenase, resulted in significantly increased PHB production from either glucose or xylose as substrate. RESULTS In this study, the xylose isomerase (EC:5.3.1.5), xylulokinase (EC:2.7.1.17) and the arabinose/xylose transport protein from Bacillus subtilis 168 (encoded by xylA, xylB and araE, respectively) were co-expressed in the ndh knockout strain, E. coli LJ03(pBHR68), which harbors the PHB biosynthesis genes from Ralstonia eutropha. The resulting strain E. coli LJ03(pBHR68+pM-ABE) was able to simultaneously utilize glucose and xylose to accumulate PHB. In flask cultivation, 3.67 g L−1 PHB was produced from a glucose–xylose mixture (10 g L−1 glucose and 5 g L−1 xylose), which was 2.09-fold higher than the production of the control strain E. coli JM109(pBHR68+pM-ABE). Ultimately, PHB production in fed-batch fermentation reached a maximum titer of 21.0 g L−1, representing a 1.93-fold increase relative to the control strain. CONCLUSION Results indicated that the engineered E. coli LJ03 strain is significantly more efficient than the parent strain E. coli JM109 in producing PHB from mixed glucose–xylose feedstock. To the best of our knowledge, this is the first study describing the implementation of an exogenous xylose utilization pathway in E. coli for the production of PHB from mixed glucose–xylose feedstock – a model of lignocellulosic hydrolysate. © 2017 Society of Chemical Industry |
| Databáze: | OpenAIRE |
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